/*
 *  Copyright 2010-2011, Social Music Discovery project
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *      * Redistributions of source code must retain the above copyright
 *        notice, this list of conditions and the following disclaimer.
 *      * Redistributions in binary form must reproduce the above copyright
 *        notice, this list of conditions and the following disclaimer in the
 *        documentation and/or other materials provided with the distribution.
 *      * Neither the name of Social Music Discovery project nor the
 *        names of its contributors may be used to endorse or promote products
 *        derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL SOCIAL MUSIC DISCOVERY PROJECT BE LIABLE FOR ANY
 *  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.socialmusicdiscovery.rcp.event;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;

/**
 * An instance that can be observed by a {@link PropertyChangeListener}.
 * This is a vital but not crucial enabler for the JFace databinding framework, 
 * but is also useful for other purposes.   
 *  
 * @author Peer Törngren
 *
 */
public interface Observable {

	/** @see PropertyChangeSupport#addPropertyChangeListener(PropertyChangeListener) */
	void addPropertyChangeListener(PropertyChangeListener listener);

	/** @see PropertyChangeSupport#addPropertyChangeListener(String, PropertyChangeListener) */
	void addPropertyChangeListener(String propertyName, PropertyChangeListener listener);

	/** @see PropertyChangeSupport#getPropertyChangeListeners() */
	PropertyChangeListener[] getPropertyChangeListeners();

	/** @see PropertyChangeSupport#getPropertyChangeListeners(String) */
	PropertyChangeListener[] getPropertyChangeListeners(String propertyName);

	/** @see PropertyChangeSupport#hasListeners(String) */
	boolean hasListeners(String propertyName);

	/** @see PropertyChangeSupport#removePropertyChangeListener(PropertyChangeListener) */
	void removePropertyChangeListener(PropertyChangeListener listener);

	/** @see PropertyChangeSupport#removePropertyChangeListener(String, PropertyChangeListener) */
	void removePropertyChangeListener(String propertyName, PropertyChangeListener listener);


	/**
	 * Fire a {@link PropertyChangeEvent} for supplied property name. No old or
	 * new value is sent. This is useful for sending "refresh events" to notify
	 * listeners that they need to update although the property has not
	 * necessarily changed.
	 * 
	 * @param propertyName
	 */
	void firePropertyChange(String propertyName);

}